Question

我想添加一个名为pHash的外部库。我将此添加到.pro文件中：

win32:CONFIG(release, debug|release): LIBS += -L$PWD/Libs/pHash-0.9.4/release -lpHash
else:win32:CONFIG(debug, debug|release): LIBS += -L$PWD/Libs/pHash-0.9.4/debug -lpHash

INCLUDEPATH += $PWD/Libs/pHash-0.9.4
DEPENDPATH += $PWD/Libs/pHash-0.9.4

win32:CONFIG(release, debug|release): PRE_TARGETDEPS += $PWD/Libs/pHash-0.9.4/release/pHash.lib
else:win32:CONFIG(debug, debug|release): PRE_TARGETDEPS += $PWD/Libs/pHash-0.9.4/debug/pHash.lib

但是该库的任何功能都没有起作用。当我尝试使用一个时，我会产生错误＆＃34;对pHashFunction＆＃34;的未定义引用。有一个使用的例子：

#include "myclass.h"

#define HAVE_IMAGE_HASH 1 // config
#include "pHash.h"

void MyClass::perform() {
    const char *msg = ph_about();
    qDebug() << msg;
}

然后是构建日志：

C:/Qt/Tools/mingw492_32/bin/mingw32-make -f Makefile.Debug clean
mingw32-make[1]: Entering directory 'C:/Users/vi/Documents/Programmation/QtWorkspace/build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug'
rm -f debug/qrc_qml.cpp
rm -f debug/moc_myclass.cpp
rm -f debug/main.o debug/myclass.o debug/qrc_qml.o debug/moc_myclass.o
mingw32-make[1]: Leaving directory 'C:/Users/vi/Documents/Programmation/QtWorkspace/build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug'
C:/Qt/Tools/mingw492_32/bin/mingw32-make -f Makefile.Release clean
mingw32-make[1]: Entering directory 'C:/Users/vi/Documents/Programmation/QtWorkspace/build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug'
rm -f release/qrc_qml.cpp
rm -f release/moc_myclass.cpp
rm -f release/main.o release/myclass.o release/qrc_qml.o release/moc_myclass.o
mingw32-make[1]: Leaving directory 'C:/Users/vi/Documents/Programmation/QtWorkspace/build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug'
01:31:34: Le processus "C:\Qt\Tools\mingw492_32\bin\mingw32-make.exe" s'est terminé normalement.
01:31:34: Configuration inchangée, étape qmake sautée.
01:31:34: Débute : "C:\Qt\Tools\mingw492_32\bin\mingw32-make.exe" 
C:/Qt/Tools/mingw492_32/bin/mingw32-make -f Makefile.Debug
mingw32-make[1]: Entering directory 'C:/Users/vi/Documents/Programmation/QtWorkspace/build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug'
g++ -c -pipe -fno-keep-inline-dllexport -g -frtti -Wall -Wextra -fexceptions -mthreads -DUNICODE -DQT_QML_DEBUG -DQT_DECLARATIVE_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_NEEDS_QMAIN -I../myProject -I. -I../myProject/Libs/pHash-0.9.4 -IC:/Qt/5.5/mingw492_32/include -IC:/Qt/5.5/mingw492_32/include/QtQuick -IC:/Qt/5.5/mingw492_32/include/QtGui -IC:/Qt/5.5/mingw492_32/include/QtANGLE -IC:/Qt/5.5/mingw492_32/include/QtQml -IC:/Qt/5.5/mingw492_32/include/QtNetwork -IC:/Qt/5.5/mingw492_32/include/QtCore -Idebug -IC:/Qt/5.5/mingw492_32/mkspecs/win32-g++  -o debug/main.o ../myProject/main.cpp
g++ -c -pipe -fno-keep-inline-dllexport -g -frtti -Wall -Wextra -fexceptions -mthreads -DUNICODE -DQT_QML_DEBUG -DQT_DECLARATIVE_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_NEEDS_QMAIN -I../myProject -I. -I../myProject/Libs/pHash-0.9.4 -IC:/Qt/5.5/mingw492_32/include -IC:/Qt/5.5/mingw492_32/include/QtQuick -IC:/Qt/5.5/mingw492_32/include/QtGui -IC:/Qt/5.5/mingw492_32/include/QtANGLE -IC:/Qt/5.5/mingw492_32/include/QtQml -IC:/Qt/5.5/mingw492_32/include/QtNetwork -IC:/Qt/5.5/mingw492_32/include/QtCore -Idebug -IC:/Qt/5.5/mingw492_32/mkspecs/win32-g++  -o debug/myclass.o ../myProject/myclass.cpp
In file included from ../myProject/myclass.cpp:3:0:
../myProject/Libs/pHash-0.9.4/pHash.h:299:21: warning: 'cimg_library::CImg<float>* ph_dct_matrix(int)' declared 'static' but never defined [-Wunused-function]
 static CImg<float>* ph_dct_matrix(const int N);
                     ^
'C:\Qt\5.5\mingw492_32\bin\rcc.exe' -name qml ../myProject/qml.qrc -o debug/qrc_qml.cpp
g++ -c -pipe -fno-keep-inline-dllexport -g -frtti -Wall -Wextra -fexceptions -mthreads -DUNICODE -DQT_QML_DEBUG -DQT_DECLARATIVE_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_NEEDS_QMAIN -I../myProject -I. -I../myProject/Libs/pHash-0.9.4 -IC:/Qt/5.5/mingw492_32/include -IC:/Qt/5.5/mingw492_32/include/QtQuick -IC:/Qt/5.5/mingw492_32/include/QtGui -IC:/Qt/5.5/mingw492_32/include/QtANGLE -IC:/Qt/5.5/mingw492_32/include/QtQml -IC:/Qt/5.5/mingw492_32/include/QtNetwork -IC:/Qt/5.5/mingw492_32/include/QtCore -Idebug -IC:/Qt/5.5/mingw492_32/mkspecs/win32-g++  -o debug/qrc_qml.o debug/qrc_qml.cpp
'C:\Qt\5.5\mingw492_32\bin\moc.exe' -DUNICODE -DQT_QML_DEBUG -DQT_DECLARATIVE_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_NEEDS_QMAIN -D__GNUC__ -DWIN32 -IC:/Qt/5.5/mingw492_32/mkspecs/win32-g++ -IC:/Users/vi/Documents/Programmation/QtWorkspace/myProject -IC:/Users/vi/Documents/Programmation/QtWorkspace/myProject/Libs/pHash-0.9.4 -IC:/Qt/5.5/mingw492_32/include -IC:/Qt/5.5/mingw492_32/include/QtQuick -IC:/Qt/5.5/mingw492_32/include/QtGui -IC:/Qt/5.5/mingw492_32/include/QtANGLE -IC:/Qt/5.5/mingw492_32/include/QtQml -IC:/Qt/5.5/mingw492_32/include/QtNetwork -IC:/Qt/5.5/mingw492_32/include/QtCore -I. ../myProject/myclass.h -o debug/moc_myclass.cpp
g++ -c -pipe -fno-keep-inline-dllexport -g -frtti -Wall -Wextra -fexceptions -mthreads -DUNICODE -DQT_QML_DEBUG -DQT_DECLARATIVE_DEBUG -DQT_QUICK_LIB -DQT_GUI_LIB -DQT_QML_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_NEEDS_QMAIN -I../myProject -I. -I../myProject/Libs/pHash-0.9.4 -IC:/Qt/5.5/mingw492_32/include -IC:/Qt/5.5/mingw492_32/include/QtQuick -IC:/Qt/5.5/mingw492_32/include/QtGui -IC:/Qt/5.5/mingw492_32/include/QtANGLE -IC:/Qt/5.5/mingw492_32/include/QtQml -IC:/Qt/5.5/mingw492_32/include/QtNetwork -IC:/Qt/5.5/mingw492_32/include/QtCore -Idebug -IC:/Qt/5.5/mingw492_32/mkspecs/win32-g++  -o debug/moc_myclass.o debug/moc_myclass.cpp
g++ -Wl,-subsystem,windows -mthreads -o debug/myProject.exe debug/main.o debug/myclass.o debug/qrc_qml.o debug/moc_myclass.o  -lmingw32 -LC:/Qt/5.5/mingw492_32/lib -lqtmaind -lshell32 -LC:/Users/vi/Documents/Programmation/QtWorkspace/myProject/Libs/pHash-0.9.4/debug -lpHash -lQt5Quickd -lQt5Guid -lQt5Qmld -lQt5Networkd -lQt5Cored 
debug/myclass.o: In function `ZN6myclass7performEv':
C:\Users\vi\Documents\Programmation\QtWorkspace\build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug/../myProject/myclass.cpp:11: undefined reference to `ph_about'
collect2.exe: error: ld returned 1 exit status
Makefile.Debug:83: recipe for target 'debug/myProject.exe' failed
mingw32-make[1]: *** [debug/myProject.exe] Error 1
mingw32-make[1]: Leaving directory 'C:/Users/vi/Documents/Programmation/QtWorkspace/build-myProject-Desktop_Qt_5_5_0_MinGW_32bit-Debug'
makefile:34: recipe for target 'debug' failed
mingw32-make: *** [debug] Error 2

提前感谢您的帮助：）

Answer 1

尝试将.c和.cpp添加到您在我的电脑上运行的项目（dirent.c，ph_fft.c，pHash.cpp，phcomplex.c），但我认为问题在于.dll和。 lib与您的Qt版本不兼容，因为它是用Visual Studio编译的。

Answer 2

不再支持库pHash，并且存在许多问题。

Qt使用的编译器MinGW 4.9.2与MSVC中内置的.dll文件不兼容。
使用诀窍"MSVC and MinGW DLLs"是不够的，因为函数ph_about()未从pHash.dll导出，例如Building the pHash library on Windows
< / LI>
可以将所有的pHash文件集成到Qt项目中，因此可以与应用程序一起构建库。由于库项目是为Visual Studio准备的，我会说Qt也应该基于VC。然而，库pHash是旧的。它是为Visual Studio 2008编写的。现在它在已弃用的Windows函数SHGetSpecialFolderPathA上出错。
使用Qt MinGW 4.9.2编译器编译所有内容仍然是可能的。在这种情况下，需要将DEFINES += HAVE_IMAGE_HASH=1添加到项目.pro文件中，以便为pHash编译启用该宏。但是，要使用对映像的本机支持，库libjpeg和libpng也应使用相同的编译器进行编译，例如Compiling libjpeg 如果未使用图像库，Cimg会尝试运行某些外部可执行文件gm.exe（可能来自GraphicsMagick）。

如果某个快速任务需要库，则可以考虑使用虚拟Linux，因为在这里它可以直接使用https://stackoverflow.com/a/33002746/4023446

Qt5 - 链接pHash库＆＃34;未定义参考＆＃34;

2 个答案: